This invention relates to a control device for a cooking apparatus with a timer function which utilizes an interruption procedure and, more particularly, to a control device for use in a cooker having a cooking time-setting function, such as a microwave range.
A cooker such as a microwave range generally has an operation panel on the front surface of its housing. A rotary operation knob with a cooking time-setting scale is arranged on the operation panel. The operation knob is connected to an operation shaft of a variable resistor at the rear side of the operation panel. A voltage signal based on a change in resistance of the variable resistor is converted into a digital signal by and A/D (Analog/Digital) converter. The digital signal is input, as cooking time-setting information, to a controller. The controller includes a microprocessor and its peripheral circuits, and it controls the overall operation of the microwave range on the basis of the cooking time-setting information and other input information.
When a user wishes to cook food, in practice, he or she turns the operation knob while observing the cooking time-setting scale on the operation panel, thereby setting a desired cooking time. The user then depresses a cooking-start key.
In a conventional microwave range of this type, as noted above an A/D converter is used to convert an output from a variable resistor into a digital signal. However, since the A/D converter is expensive, it is one of the main factors accounting for an increase in the total cost of the cooking apparatus. In addition, maximum and minimum values of the cooking time-setting scale on the operation panel are limited. Such limitations restrict a maximum value usable for time-setting and often result in time-setting errors.